The objective of the proposed research is the isolation and structural characterization of naturally occurring chromium(III) complexes which potentiate the action of insulin in the metabolism of glucose. These complexes will be isolated from food sources and have been coined Glucose Tolerance Factor (GTF). Purified GTF complexes may then be employed in the treatment of certain forms of diabetes (glucose intolerance) and possibly, atherosclerosis (abnormal lipid metabolism) induced by dietary chromium deficiency. Certain aspects of the mechanism of the action of insulin will also be investigated. The nature of the molecular interaction of purified GTF with insulin and insulin receptors located on isolated rat adipocytes will be explored.